Medical Testing on Animals: A Brief History

January 27, 2015

Animals are used in biomedical research for everything from basic understanding and exploratory research to drug and vaccine development. The use of animals as models in medical research has existed since the beginnings of medicine and has led to the discovery and creation of treatments and cures for a long list of ailments. It is not the purpose of this blog post to argue against the well-known fact that the use of non-human animals in biomedical research has given important contributions to the medical progress. However, awareness and knowledge of the types of procedures animals are subjected to for the purpose of scientific and medical progress provides for an educated, public, scientific and philosophical debate on a long-standing and controversial topic. This blog post explores the thoughts, beliefs, and scientific advancements surrounding animals and their place in the biomedical research world throughout history.

Early Greek physician-scientists, who believed that nature could be understood by exploration and experiments, dissected animals for anatomical studies and to satisfy anatomical curiosity. Animals were used as experiment and test subjects, although, it appears that humans, specifically criminals, were also used in biomedical research and experiments at the time.

Dissections performed on animals are called vivisections, defined as the exploratory surgery of live animals. During vivisections, physician-scientists examine sensory nerves, motor nerves and tendons in order to understand their functional differences.[1] In the 12th Century, Arabian physician Ibn Zuhr introduced animal testing as an experimental method for testing surgical procedures before applying them to human patients.[2] Zuhr’s work showed research on animals in the medical field, taking animal experiments beyond mere understanding and exploration of the body. He used these methods of research for practice, in contrast to the exploratory research in the Greek tradition.

In order to understand, even briefly, the ancient thoughts towards vivisection and experimentation on live animals, it is essential to remove oneself from the thoughts of today and approach the subject matter with the knowledge and beliefs of the time period. The Christian Church subscribed to the view that humans did not share a common lineage with other animals, and for most ancient Greeks, using live animals in experiments did not raise any relevant moral questions.[3] This view of man’s superiority is represented in several works throughout the ages.

Throughout the Age of Enlightenment (c. 17th Century), physiological experiments on animals were carried out for the purpose of scientific progress. French philosopher, René Descartes, performed vivisections on animals under his belief that animals were ‘machine-like’, interpreted as a belief that animals could not feel pain. Other philosophers, including Baruch Spinoza (1632-1677), did not deny animals’ ability to feel, but considered humans should nevertheless use them as we please and treat them in a way which best suits us.[4] Alternatively, Immanuel Kant (1724-1804) acknowledged the sentience of other species.

At this point, the thoughts on the use of animals in research went from animals being here to serve humankind in any way we see fit, to the acknowledgement of their sentience and the fact that they could feel pain, but the justification that their pain was a necessary evil.

Over the seventeenth century, animal experiments would prove to be more informative and relevant in obtaining scientifically sound knowledge. However, the moral acceptability of inducing suffering in animals in the name of scientific advancement also became an issue raised in opposition of vivisection before the end of the seventeenth century. Yet even those who acknowledged that animals suffered through experiments, nevertheless defended themselves against the accusation of cruelty by alleging that the suffering of animals in the name of science was justified for the sake of humankind. This defence is not unfamiliar today.

The 18th Century marked the rise of moral consideration for animals. Stephen Hales (1677-1761) was the first to measure pressure in the blood vessels, and contributed significant advancements in the understanding of cardiovascular and respiratory physiology. Albrecht Von Haller (1708-1777) is known for his work on inflammation, neurophysiology, heart function, and hemodynamics.[5] It is common knowledge that both researchers were disgusted by the gruesomeness of their own experiments and were concerned about their moral justification, but nevertheless carried on, certain of the need for the use of live animals for the comprehension of many basic physiological processes, which were far from being understood.[6] Again, here we see similar approaches to what we experience today in regard to the use of animals and their essential contribution to scientific and medical discoveries and advancements. The knowledge gained justified the suffering of animals.

By the beginning of the 19th Century, the topic of discussion was not if animals could feel or not and to what extent, but rather, whether vivisection was justifiable based on the benefit for humans derived from it. While the second half of the nineteenth century marked the beginning of scientifically meaningful and medically relevant animal research, this period also saw opposition to vivisection becoming widespread in England.[7] However, while the opposition to vivisection was building in England, the same was not true in France and Germany. French physician-physiologist, François Magendie (1783-1855), is described as the founder of modern physiology. There was broad recognition of his contributions to science as he was among the first to determine that many bodily processes resulted from the co-functioning of several organs. This realization began numerous experiments that involved manipulative procedures rather than just internal observations.[8]

Magendie was among the most infamous of his time for the types of experiments he conducted and the cruelty they entailed. His public presentations became the most notorious, particularly one he performed in England when he dissected a dog’s facial nerves while the animal was nailed down by each paw and was left overnight for further dissection the following day.[9] Magendie’s student, Claude Bernard (1813-1878), followed in his teacher’s steps, responding to the growing number of critics of vivisection by posing that humans have the whole and absolute right to make experiments on animals, including vivisection. Furthermore, with the discovery of anesthetic, which allowed for experiments on animals to continue with less guilt because less pain was being induced, animal experimentation became routine in the 1840s.

Opposition to the use of animals for research is not an entirely modern phenomenon. In the early and mid-nineteenth century, the availability of general anesthetics and the increasing popularity of domestic pets, fuelled anti-vivisection sentiments. As the number of experiments had increased over time, so too had resistance to them.[10] The professional physiologists and those scientists conducting the experiments were some of the first to record their uneasiness with vivisection. Later, as these sentiments were popularized, it was at first in regard to the fundamental differences between humans and non-human animals; an argument that is still alive today.

Utilitarianism professed that the only good was pleasure and the only evil was pain. To be a utilitarian meant that one should act to produce the greatest balance of pleasure over pain.[11] American philosopher, Tom Regan, asserted that animal research should be abolished, arguing that no ends can justify the evil means of sacrificing an animal in the face of inviolable dignity of sentient beings.[12] By this time, animal anti-cruelty societies had been formed and were concerned with abolishing animal research along with cock and dog fighting and bull baiting. The ethics surrounding the sentience of animals and whether or not they had rights, and the discussions pertaining to these issues, truly entered the public discourse in the 1870s, which was closely followed by the enactment in England of the Cruelty to Animals Act (the Act) in 1876.

In 1874, Queen Victoria expressed her own concern over the treatment of animals, which coincided with wide-scale English public opposition in the 1870s. In 1875, the Victoria Street Society for the Protection of Animals Liable to Vivisection, the first society for animal protection, was founded. The public debate surrounding vivisection led to the enactment of the Act. The Act prohibited painful experiments on animals, subject only to restrictions imposed by the Act. The general restrictions included that experiments must be performed with a view to the advancement by discovery of physiological knowledge which can be useful for saving or prolonging life or alleviating suffering. It also outlined that the animal must be under some anesthetic during the whole procedure in order to prevent the animal from feeling pain and if the pain will continue after the procedure, the animal must be killed before it recovers from the influence of the anesthetic.[13] Although it did not prohibit all animal vivisection, this Act did require the use of anesthetics for many types of animal experimentation. The Act set limits on the practice of, and instituted a licensing system for, animal experimentation. It was replaced years later by the Animals Act 1986.

The movement against animal testing in North America began in earnest around 1980. Australian philosopher Peter Singer wrote Animal Liberation in 1975, arguing that the interests of animals should be considered because of their ability to feel suffering and that the idea of rights was not necessary to weigh against the relative worth of animal experimentation. Later, books such as Richard Ryder’s Victims of Science and Bernard Rollin’s Animal Rights and Human Morality were crucial publications in the resurgence of popular interest in animal welfare. With the realities of how animals were being treated becoming somewhat public knowledge, scientists could no longer defend all experiments as some of their predecessors had done. They were challenged to defend their practices in a philosophical arena and to demonstrate a morally relevant distinction between human and non-human beings that could justify the use of one but not the other in laboratory experiments.[14] Just as today, there were also those who valued both animal protection and scientific progress and, recognizing that each side had both accurate and erroneous arguments, found themselves in the middle-ground, and sought compromise and progress.[15]

Understanding how we got to where we are, both scientifically and ethically will help us to better understand where our present society stands in regard to the biomedical research being conducted today. Today, biomedical research is a multi-billion dollar industry, encompassing pharmaceutical and chemical industries, universities and government bodies, among others.[16]

The history of animal-based research is appalling; experiments conducted upsetting; and the view of animals as below humans problematic. While experiments have become more humane, we still view our lives as superior – an approach that is supported by the fact that animals, and not humans, are still being used in research for our benefit. The history in this area has marked encouraging progress, but there is a great deal of progress still to be made.

This blog and the contents herein are for informational purposes only and do not constitute legal advice. Readers are advised to seek legal counsel prior to acting on any matters discussed herein. The opinions expressed are those of the author.